Lightweight, high-power output power plants have particular application to small, unmanned aircraft, but can be applied in other fields as well. Relatively small battery powered power plants of this type have been developed and used, but such power plants suffer from lower power output and substantial weight. There are many applications, particularly in the aircraft field, where a lightweight electric power plant with a relatively high power output could be used to great advantage. Such applications include remotely piloted vehicles for reconnaissance, electronic warfare and munitions delivery.
Electrochemical or metal/air batteries can produce large quantities of power for relatively substantial periods of time. Electrochemical metal/air batteries are well known in the art, examples of which may be found in U.S. Pat. Nos. 3,378,406, 4,871,627, 3,468,711, 4,828,939 and 4,925,744, each of which is incorporated herein by reference.
In view of these requirements, there is a need for a lightweight, electrically driven turbofan engine which has a relatively small size and high power to weight ratio.